1. Field of the Invention
The present invention relates to a plasma display module and, more particularly, to a plasma display module having an improved grounding structure.
2. Description of the Related Art
A plasma display module is a flat panel display module that displays images using a gas discharge phenomenon, and is highlighted as a next generation flat panel display module that can substitute for a cathode ray tube (CRT) because a plasma display module has excellent display characteristics such as display capacity, brightness, contrast, residual image, and wide viewing angle.
The plasma display module includes a plasma display panel (PDP), on which varying video images may be displayed, and a chassis base that is disposed to face the PDP.
The PDP is formed by combining a front panel and a back panel, and the front panel and the back panel respectively include a plurality of sustain electrode pairs and a plurality of address electrodes. In addition, discharge cells are disposed between the front panel and the back panel.
The plasma display module having the above described structure displays the images by selectively discharging the discharge cells. Thus, a circuit board, on which a circuit device that generates a control signal is mounted, is mounted on the chassis base. The signal generated by the circuit device is transmitted to an electrode of the panel through a connection cable, for example, a flexible printed circuit (FPC).
In order to apply an accurate driving signal stably to the panel electrode however, a reference voltage (that is, a voltage on a grounding line) should be constantly maintained in a circuit network that generates and transmits the signal as described above.
According to conventional practice in the art, the grounding line of the connection cable is electrically connected to a ground area of the circuit board, and the ground area of the circuit board is grounded to the chassis base, thus the connection cable is indirectly grounded to the chassis base through the circuit board.
Since the grounding of the connection cable is electrically connected through the circuit board however, the length of the reference voltage line increases, and accordingly, resistance of the line is increased and the line becomes vulnerable to noises generated in internal and external portions of the module. Thus, the reference voltage can not be constantly maintained. In addition, since the structure of grounding becomes more complex as the length of the reference voltage line is increased, the stability of the grounding is lowered and grounding defects may be created by external shock or vibration. More significantly, the structural dimensions of the discharge cell have become super-fine recently; thus, even more circuit devices and connection cables are mounted on the cell. We have found that, the grounding structure should therefore be improved.